Bill Haney devotes only one-third of his time to filmmaking. But at this precise moment, he’s 100 percent focused on “The Last Mountain,” his documentary about the coal-mining technique known as “mountaintop removal.’’

The movie covers a range of issues, from health and safety to the future of the national economy. In conversation, Haney reaches much further, invoking the American Revolution and World War II. The battle over coal mining in West Virginia is an opportunity, he contends, “to stand up for democratic principles that Americans have spilled blood over for 300 years.”

“The Last Mountain,” which opens Friday, was sparked by three things, the filmmaker explains over lunch at a restaurant on M Street NW. The first two are the community activists “around Coal River Mountain who stood up against the most powerful interest in their state’” and “the obliteration of the landscape and the environment in Appalachia.”

The other inspiration is about to join Haney at the table: lawyer, activist and entrepreneur Robert F. Kennedy Jr., whose 2004 book, “Crimes Against Nature,” awakened the director’s interest in mountaintop mining.

Kennedy, who didn’t help make the film but is a major figure in it, addresses mountaintop mining as if he’s giving a stump speech. “It’s the worst man-made environmental disaster on the North American continent,” he says in a voice made quavery by spasmodic dysphonia, a neurological condition of the larynx.

“It’s also a template for every environmental issue,” he continues, “because it has all the ingredients, including the subversion of democracy and the colonial effect of corporate power on localities. Large corporations come and subdue the people and extract the wealth. And leave impoverished, devastated culture and society behind.”

Recalling his father’s 1960s interest in Appalachia, Kennedy says: “Coal doesn’t bring prosperity. It brings poverty and destruction.” The coal companies, he says, “have meticulously and ruthlessly and mercilessly replaced human labor with bombs and machines.”

He eats a club sandwich with two extra orders of mayonnaise, which he spreads as liberally as he does statistics: Massey Energy, the movie’s corporate villain, committed 67,000 violations of the Clean Water Act in five years, he says. And coal companies detonate 25,000 tons of explosives daily in West Virginia, “the equivalent of a Hiroshima bomb once a week.”

Like Kennedy’s comments, “The Last Mountain” is unabashedly polemical. The film provides evidence of catastrophic health problems, resulting from high levels of lead, mercury and other metals in drinking water, and flood hazards, from earth dams that hold (or fail to hold) water contaminated by toxic sludge.

The movie’s credibility is boosted by the weakness of its opposition: Massey Energy has been on the retreat since the April 2010 disaster at its Upper Big Branch mine, where 29 miners were killed as the result of a methane-gas explosion.

“One of the horrors of making this movie,” Haney says, “was that when we plumbed Massey’s safety standards, you could feel it was going to happen again. And then it did.”

Former Massey president Don Blankenship, a global-warming denier who resigned after the catastrophe, does appear in the documentary. But Haney says he didn’t use many of his remarks “because it looks like you’re mocking the guy.”

Massey merged this week with Alpha Natural Resources. A spokeswoman for that company, Karen Hanretty, said the firm did not have a specific response because “we haven’t seen the movie.”

“There are a lot of laws and regulations that the coal industry has to abide by,” she added. “While we’re not perfect, we aim to abide by those laws and regulations.”

According to the filmmaker, “The Last Mountain” faithfully presents all — that is, both of — the arguments for exploding peaks to get the minerals beneath. “The coal industry in our film has two things to say: Coal’s what keeps the lights on; we need the jobs,” Haney says. “Bobby has engaged in these very thoughtful debates with them, and they endlessly say these two things.

“The truth is, there are better ways to keep the lights on. And there are better ways to have jobs.”

Haney is not a disinterested observer on the subject. He’s probably best known as the director of such documentaries as “The Price of Sugar,” about exploited workers in the Dominican Republic, and the scripter of “American Violet,” a docudrama about a Texas police force that framed African Americans in drug cases. But before that, as a Harvard undergraduate, he started a company that designed and sold equipment to reduce emissions from power plants.

“We’re on 600 plants right now,” he says.

Currently, Haney runs Blu, which makes prefab homes “that drop your carbon footprint by 75 percent.” (The other third of his time is devoted to World Connect, a charity that works with women and children in 15 developing countries.)

Kennedy, who attended Harvard about a decade before Haney, is also putting his money into the emission-reducing business. He’s an investor in BrightSource Energy, which is constructing a 2.7-gigawatt solar-thermal plant in the Mojave Desert. “Once we build it,” he says, “it’s free energy forever. The photons are hitting the Earth for free. All we have to do is build the infrastructure to harvest them and put them on the line.”

Renewable energy is part of the movie’s story. West Virginia activists proposed erecting windmills atop Coal Mountain to generate energy without demolishing the ridge. That hasn’t happened, but Kennedy is convinced that wind power — which also has its critics — will eventually help replace coal.

“According to the Bureau of Labor Statistics, there are 85,000 coal miners in this country,” he says, noting that this is a huge reduction from 20 or 30 years ago. “And there’s, I think, 86,000 employed in the wind industry. So you’ve already seen that crossover take place.’’

Both Haney and Kennedy look to the Obama administration’s Environmental Protection Agency to reform coal-mining practices. But Kennedy says the long-term answer is “free-market capitalism,” without the existing subsidies to the extraction industries: coal and oil.

“The new energy economy, which can be such a wonderful source of jobs, is already happening right before us, even with all tax credits stacked against us,’’ Haney says.

“At the heart of this story is a can-do attitude for America,’’ he concludes. “America takes a while to wake up, but when it wakes up, it’s extremely effective.”

Jenkins is a freelance writer.